This was an interesting premise for an episode. Nuoh covets round things and steals the GS Ball (back when we all thought it was going to be important), which is a pretty decent idea - although I wonder why they chose Nuoh as the Pokémon of the day for this episode. As far as I can recall, there's nothing in the games about it liking round objects, and I suspect they just chose it at random.
Also, this episode features an aspect of the Jouto episodes that was present in the Donfan and Kereihana episodes that I didn't mention then, but still really bugs me - whenever they debut an evolved Pokémon before its base form, they don't mention its base form at all. All these Nuoh running around and we don't even hear anyone mention Upaa, let alone see one. I suspect this was done deliberately, so that each Pokémon could be treated as a standalone creature and guarantee that they'd get one episode devoted exclusively to them and them alone. Gotta get as many episodes as we can out of this saga - why burn off Upaa and Nuoh in one episode when we can split 'em into two?
This episode isn't stellar, but it does have its laugh-out-loud moments. The stuff with Musashi-tachi is good, of course, and again, they provide the highlight of the episode - trying to snare the slippery Nuoh and reciting their motto with increasing frustration at the same time. That's bravura voice acting from both Hayashibara Megumi and Shin'ichirou Miki right there.
Also, that scene on the bridge where Nuoh just shows up out of nowhere and makes a grab for the GS Ball, and Chikorita goes ballistic at the prospect of anybody else hugging her Satoshi - that made me laugh too. Already, Chikorita is showing more signs of personality in two episodes than Heracross has shown in ten.